ASP.NET Web PDF Document Viewer/Editor Control Library

Listing 6-8. Writing Error Messages to a Table SQL> CREATE OR REPLACE PROCEDURE error_log(error__msg in varchar2, procedure_name IN VARCHAR2 IS PRAGMA AUTONOMOUS_TRANSACTION; BEGIN INSERT INTO log_table (error_msg, procedure_name) VALUES (error_msg,procedure_name)); COMMIT; EXCEPTION WHEN OTHERS THEN ROLLBACK; END; SQL> Autonomous transactions can serve other purposes in the Oracle database. For example, they can enable the handling of nonstandard PL/SQL coding issues, such as using DDL statements in triggers. Autonomous transactions also are useful in performing an audit of database queries and failed (unauthorized) database activity. Listing 6-9 shows an example in which the autonomous transaction feature is used to audit (presumably) unauthorized update activity. Even when a user is unsuccessful in the update attempt, the user s name can be successfully logged into an audit table if you code a simple pair of triggers that use the autonomous transaction feature. Listing 6-9. Using an Autonomous Transaction to Audit Database Activity SQL> CREATE OR REPLACE TRIGGER aud_bef_trig BEFORE INSERT ON emp FOR EACH ROW DECLARE PRAGMA AUTONOMOUS_TRANSACTION BEGIN INSERT INTO audit_employee VALUES ( :new.username, 'before insert', sysdate); COMMIT; END; SQL> CREATE OR REPLACE TRIGGER aud_aft_trig AFTER INSERT ON emp FOR EACH ROW DECLARE PRAGMA AUTONOMOUS TRANSACTION BEGIN INSERT INTO audit_emp VALUES ( :new.username, 'after insert', sysdate); COMMIT; END; SQL> Note that you can t always just use a pair of normal triggers to audit database activity because auditing data provided by the triggers won t be recorded if the triggering statement is rolled back.

how to install barcode font in excel 2007, how to create barcode in excel 2010, barcode excel 2007, barcode in excel 2010 free, barcode generieren excel freeware, free barcode generator excel 2010, create barcode in excel, barcode add in for excel 2007, how to make barcodes in excel 2007, free barcode addin for excel 2007,

Imagine you re running a very long batch job and it runs out of space for some reason, whether because of an unexpected amount of data or because of a failure to notice that the space was running out for the objects involved in the DML transactions. Or perhaps there was a maximum number of extents reached error. What are your options when this sort of thing happens (as it inevitably will)

Most of the time, you must correct the space problem or other condition that caused the error in the first place, and then restart your transactions. More often than not, you will roll back the whole operation, which will take quite a bit of time. Sometimes you have to restart at the very beginning of the program, which is a waste of time. In any case, your actions as a DBA are limited to playing catch-up after the fact to rectify the error and redo the operation. Oracle s Resumable Space Allocation feature will suspend database operations that run into problems due to lack of space, and it restarts those operations automatically when the space problems are fixed. The Resumable Space Allocation feature comes in handy when you re trying to ensure that key batch jobs or data loads run within the window of operation they are allotted when they encounter space-related issues.

Most .NET languages do not use this feature, but for C++/CLI interoperability, this feature is essential. IL supports pointers of any type and any level. For example, the C++ type double*** would be mapped to the IL type float64***. To perform read and write operations via a pointer, the IL instruction set has special instructions. To understand these instructions, assume that f is implemented as follows: void f(int* pi) { *pi = 42; } To map this C++ source code to IL, the C++/CLI compiler generates the following code: // *pi = 42; ldarg.0 ldc.i4 42 stind.i4 // // // // // Push the first argument (int* pi) on the stack Push 42 as a 4-byte integer value on the stack Pop the top two elements of the stack, store the value in the top element in the address specified by the top - 1 element on the stack

Oracle uses temporary tablespaces as work areas for tasks such as sort operations for users and sorting during index creation. Oracle doesn t allow users to create objects in a temporary tablespace for permanent use in the database. By definition, the temporary tablespace holds data only for the duration of a user s session, and the data can be shared by all users. The performance of temporary tablespaces is extremely critical when your application uses sort- and hash-intensive queries, which need to store transient data in the temporary tablespace.